EP0627876A1 - Manufactoring method of an electromagnetically sealed support of two metallic components and a shielded circuit board with such components - Google Patents

Abstract

The first component (S1, S2, S3) has a groove (N) on its top (OS). This groove (N) is preferably located on the edge of the top (OS) and is preferably covered by a laminate (L) as an extension of the top. The second component (B1, B2, B3, B4) has a blade-like insertion region (EB). In the case of a first configuration of the invention, stamped studs (P1) in the region of the laminate (L) are introduced into the surface (OS) of the first component (S1, S2, S3) after insertion of the insertion region (EB) of the second component (B1, B2, B3) into the groove (N) (Fig. 1a-4b). In the case of a second embodiment of the invention, the stamped studs (P2) are introduced into the blade-like insertion region (EB) of the second component. The two components (S1, B4) are then fixed, after the insertion region (EB) of the second component (B4) has been inserted into the groove (N) in the first component (S1), by peening the stamped studs (P2) in the interior of the groove (N) (Fig. 5a, 5b). <IMAGE>

Description

The invention relates to a method for the electromagnetically sealed mounting of two metallic components, and shielded subrack for mounting electronic assemblies.

So-called "embossed knobs" can be pressed into thin-walled sheets or profiles, preferably made of aluminum. With this pressure forming, the surface of the thin-walled sheet or profile is changed on both sides, e.g. cylindrical stamp is pressed into the sheet. This creates a cylindrical depression in the surface of the sheet metal facing the stamp, while the material bulges like a knob on the opposite upper side. If the punch diameter and indentation are correctly matched to the thickness and type of the respective sheet, knobs can be shaped with an almost ideal cylindrical shape. The cylindrical knobbed jacket is thus approximately perpendicular to the sheet surface. Thin-walled aluminum sheets are particularly suitable for pressing in such embossed knobs that protrude on one side.

It is known to introduce embossed knobs of the type described above into thin-walled, aluminum side parts and intermediate walls of subracks. Such subracks are, for example, in so-called "imperial" (eg 19-inch design) or in metric grid built up. They are used for the proper reception of electrical or electronic components and assemblies, in particular of various types of printed circuit boards, power supplies and the like. "Flat modules" of this type are inserted vertically and close to one another into the specially constructed and dimensioned module racks. The embossed knobs introduced into the side parts and intermediate walls of such subracks serve as positioning means, for example for connecting rails, which can be screwed to the side parts or intermediate walls at the end in the subrack.

In the case of subracks for accommodating electronic assemblies, there is often the requirement that they be designed within the framework of the so-called "electromagnetic compatibility" (EMC) in such a way that electromagnetic interference is shielded in the largest possible frequency range. In such a case, all components of a subrack need not only be connected to one another in an electrically conductive manner. Rather, all connections between the components must be made in such a way that electromagnetic interference radiation of even higher frequencies cannot penetrate the connection points.

For the electromagnetic sealing of such transition points, it is known to use additional components which often consist of special material. For example, contact spring strips made of a copper-berillium alloy for electromagnetic sealing are inserted in the joint areas, for example between connecting rails and cover plates. In other cases, for example, special tubular fabrics, which are woven from the finest wires, are used as inlays between rails and cover plates to be screwed on.

Systems of this type for electromagnetic sealing of the contact areas between two metallic components, in particular in subracks, not only have the disadvantage that additional, specially designed contact means are required. Rather, the exact mutual assignment of the components to be fixed to one another is made more difficult due to the interposition of the contact means during assembly. Furthermore, special measures must be taken to ensure that the mechanical stability of the connection of the components is ensured despite the interposition of contact means.

The invention has for its object to enable an electromagnetically tight fixation of two metallic components, in particular on a shielded carrier for holding electronic assemblies, in a simpler way than before.

Sick connections are known from the "Book" Components of Precision Mechanics "by O. Richter and R. v. Voss, VEB Verlag Technik Berlin, 8th edition 1959, according to chapter 285 on page 161 ff. Sick connections are connections of two nested, mostly cylindrical workpieces, the connection being made by pressing a bead into one workpiece. The workpiece that engages the other part through the bead must always be made of soft, metallic material. The workpiece held by the engagement part, however, can be made of any material be.

From the German utility model with the file number G 87 14 497.2 it is known to attach a tiered shield plate for subracks in an electrically conductive manner to a mounting rail of the subrack using V-shaped fastening springs. The tiered shield plate points to the sides of the support area rows of rectangular holes. The legs of the V-shaped fastening springs reach through these for latching to the mounting rail.

The object is achieved by the method according to claims 1 and 6. Advantageous further embodiments of the invention are contained in subclaims 2 to 5 and 7,8. According to claims 9 and 10, the invention also relates to a shielded subrack for holding electronic assemblies, in which components thereof are fixed electromagnetically close to one another by embossing knobs.

FIG 1a,1b

beispielhaft eine Schiene und ein Blech als gegenseitig elektromagnetisch dicht zu verbindende Bauteile vor und nach der Fixierung, wobei die Prägenoppen gemaß einer ersten Ausführungsform der Erfindung nach der Verbindung beider Bauteile in die Oberseite des ersten, schienenartigen Bauteiles eingebracht werden,

FIG 2a,2b

eine erweiterte Ausführung des Beispieles von FIG 1a,1b, wobei die Schiene zusätzlich einen Längsschlitz im Inneren der Nut aufweist,

FIG 3a,3b

eine erweiterte Ausführung des Beispieles von FIG 1a,1b, wobei das Blech zusätzlich Senkpunkte aufweist,

FIG 4a,4b

eine erweiterte Ausführung des Beispieles von FIG 1a,1b, wobei die Schiene zusätzlich einen Längssteg im Inneren der Nut und das Blech zusätzlich einen Längsschlitz aufweisen,

FIG 5a,5b

wiederum beispielhaft eine Schiene und ein Blech als gegenseitig elektromagnetisch dicht zu verbindende Bauteile vor und nach der Fixierung, wobei die Prägenoppen gemäß einer zweiten Ausführungsform der Erfindung vor der Verbindung der beiden Bauteile in die Oberseite des zweiten, blechartigen Bauteiles hervorstehend eingebracht sind,

FIG 6a

eine Prägenoppe mit einer herkömmlichen, annähernd zylindrischen Form,

FIG 6b,6c

bevorzugte Prägenoppen mit einer zusätzlichen Kontaktspitze am Kopfbereich, und

FIG 6d,6e

bevorzugte Prägenoppen mit abgerundeten bzw. abgeschrägten Kopfbereichen.

The invention is further explained in greater detail on the basis of the preferred exemplary embodiments shown in the figures briefly listed below. Show:

FIG 1a, 1b

an example of a rail and a sheet as mutually electromagnetically tight components before and after fixation, the embossed knobs according to a first embodiment of the invention being introduced after the connection of the two components into the top of the first, rail-like component,

FIG 2a, 2b

an extended version of the example of FIG 1a, 1b, wherein the rail additionally has a longitudinal slot in the interior of the groove,

3a, 3b

an expanded version of the example of FIG 1a, 1b, wherein the sheet additionally has countersunk points,

FIG 4a, 4b

an extended embodiment of the example of FIG 1a, 1b, the rail additionally having a longitudinal web inside the groove and the sheet additionally having a longitudinal slot,

5a, 5b

Again, by way of example, a rail and a sheet as mutually electromagnetically tight components to be connected before and after the fixing, the embossed knobs according to a second embodiment of the invention being protrudingly inserted into the top of the second sheet-like component before the two components are connected,

6a

an embossed knob with a conventional, almost cylindrical shape,

6b, 6c

preferred embossed knobs with an additional contact tip on the head area, and

6d, 6e

preferred embossed knobs with rounded or beveled head areas.

FIG. 1 a shows the basic shape of the two metallic components, which according to the invention are fixed to one another in an electromagnetically tight manner using embossing knobs. The first component S1 has a longitudinal groove N at the edge of an upper side OS, which is at least partially covered by a lamella L as an extension of the upper side OS of the component S1. The lamella is relatively thin-walled and preferably elastic to a certain extent. In the example in FIG. 1a, this first component is in the form of a transverse support rail which, for example, can be screwed vertically onto the surface of, for example, a side part or an intermediate wall of a subrack via a longitudinal bore BR on the end face. Of course, this first component can also have any other shape. It only has to have a groove in one edge, edge or shoulder area, which is covered in principle by a lamella-like extension L, as shown in FIG. 1a. The groove with the covering lamella can also be made at an angle on an outside of the body of the first component.

1 a further shows the basic shape of the second component, which is to be fixed electromagnetically tight and sufficiently mechanically stable with the first component using embossed knobs according to the invention. The second component B1 has at least one knife-like insertion area EB, which can be inserted into the groove N of the first component S1. In the example in FIG. 1a, the second component B1 has the shape of a cover plate, e.g. for an outside of a subrack, which can be inserted into the groove N of the first component S1 serving as a mounting rail. In this case, the edge region of the upper side OB of the cover plate marked with dashed lines in FIG. 1a acts as a knife-like insertion region EB for insertion into the groove N of S1. Of course, the second component can also have any other shape in this case as long as it has at least one knife-like, preferably sheet-metal-like insertion area EB.

1b shows a first embodiment for the electromagnetically tight fixation of the two components S1 and B1 according to the invention from FIG. 1a. For this purpose, the insertion area EB of the second component B1 is first inserted into the groove N of the first component S1. Then embossing knobs P1 are introduced into the surface OS of the first component S1 in the area of the lamella L. 1b shows an example of three knobs 1 introduced in a row along the longitudinal edge of L. The front embossed knob shown in section shows that it has sunk into the surface OB of the second component B1 in the insertion area EB. As a result, both mechanically fixed and electromagnetically tight mutual fixation of the two components S1 and B1 is effected in a simple manner, without any additional elements such as contact spring strips for example, would have to be inserted into the interior of the groove N.

FIGS. 2a, 2b show an expanded version. The first component S2 has an additional longitudinal slot SL1, which is located below the lamella L in the opposite base of the groove N. To fix the two components, the second component B2 is first inserted into the slot N via the insertion area. According to the illustration in FIG. 2b, the embossing knobs P1 are then pressed into the surface OS of the first component S2 lying directly above the longitudinal slot L1 in the region of the lamella L. As can be seen from the sectional illustration of the front of the three embossing knobs in FIG. 2b, the pressing in of the embossing knobs in this case causes a local sinking of material from the insertion area EB of the second component B1 into the longitudinal slot SL1 located underneath. With this embodiment, the electromagnetic tightness and the mechanical stability of the mutual connection of the components S2 and B1 can be further improved.

3a, 3b, the second component B2 has lowering points SP on the surface OB in the area of the knife-like insertion area EB, which are preferably arranged in a row along the longitudinal edge of the insertion area. These lowering points can be in the form of depressions, troughs, through bores, punchings or the like. In the example in FIG. 3a, the countersink points have the shape of bores which penetrate the surface OB of the second component B2. To mutually fix the components S1 and B3, the insertion area EB of B2 is again inserted into the groove N of S1. As per the illustration 3b, the countersunk points SP are now inside the groove and are covered by the lamella L. If the embossing knobs P1 are again introduced directly above the individual countersink points SP in the area of the lamella L into the surface OS of the first component S1, the respective knobs can press into the countersunk point below during the embossing process. The mechanical stability and the electromagnetic tightness of the connection of the components S1 and B2 can also be further improved hereby.

Further possible additions are shown in FIGS. 4a, 4b. For example, in the first component S3, the lamella L has a longitudinal web ST on the inside of the groove N. Furthermore, a longitudinal countersink slot SL2 is made in the second component B3 on the surface OB of the insertion area EB. After the insertion area EB of B3 has been inserted into the groove N of S3, the countersunk slot SL2 comes to lie approximately directly below the longitudinal web ST, as shown in FIG. 4b. In this embodiment, too, the embossed knobs P1 according to the invention are pressed directly above the longitudinal web ST or the countersunk slot SL2 in the area of the lamella L into the surface OB of the first component S3. Here, in turn, part of the longitudinal web ST is either pressed directly into the surface OB of B3 below it or a longitudinal countersink slot SL2 located below it into the surface OB of the second component B3. The mechanical stability and the tightness of the connection area between the components S3 and B3 can also be improved hereby.

Figures 5a, 5b show a second advantageous embodiment of the use of embossing knobs according to the invention for the mutual electromagnetically tight fixing of two metallic components. Here, too, the first component S1 preferably has a groove N at the edge of an upper side OS. In contrast to the representations of FIGS. 1a, 1b to 4a, 4b, it is not absolutely necessary in this case that the groove is covered by a lamella L. Rather, the groove can also be located at any point on the upper side OS of S1 and, for example, can be cut into the body of the first component S1 perpendicular to the surface OS. In this case, however, embossed knobs P2 are protrudingly inserted into the knife-like insertion area ES of the second component B4.

In the example of FIG. 5a, these embossing knobs P2 are in turn arranged in a row along the edge of the insertion area EB. In this embodiment, the insertion area of the second component is thus provided with embossed knobs before being connected to the first component. The actual fixation of the two components S1, B4 is then effected after inserting the insertion area EB of the second component B4 into the groove N of the first component S1 by jamming the embossed knobs P2 inside the groove N. This embodiment of the invention has the advantage that no further manufacturing steps are necessary after inserting the second component into the groove of the first component. Rather, both components can be completely prefabricated and then fixed to one another in an electromagnetically tight manner by simply inserting, pressing or hammering in the insertion area EB provided with embossing knobs. According to the illustration in FIG. 5b, the embossing knobs P2 rub to a certain degree into the material of the opposite groove side during this insertion process. In the example in FIG. 5b, this groove side is formed by the inside of the lamella L. This version also has the advantage that the two components S1 and B4 can be detached from one another under certain circumstances.

Finally, possible embossed knob shapes are shown in FIGS. 6a to 6e. 6a shows an embossed knob with a conventional, approximately cylindrical shape. This can be achieved by the sole action of a cylindrical stamp on the surface of a thin-walled sheet, preferably made of aluminum. In particular, it is not necessary to provide a die on the knob side during the stamping process, which in turn has a cylindrical trough into which the knob is stamped.

Finally, preferred further embossed knobs are shown in FIGS. 6b to 6e. The embossed knobs of FIGS. 6b, 6c have additional contact tips in the head region. While the embossed knob shape of FIG. 6b can be produced with the aid of an opposing, correspondingly shaped die, the embossed knob with the shape shown in FIG. 6c is created solely by the action of an embossing stamp with a conical tip. The embossed knob shapes of FIGS. 6b, 6c can be used in particular in the embodiment of the invention shown in FIGS. 5a, 5b. The electrical contacting and mechanical jamming of the embossing knobs in the insertion area EB is further improved when the second component B4 is driven into the groove of the first component S1 by the contact tips in the head region of the embossing knobs.

Finally, in contrast to the embodiments in FIGS. 6b, 6c, the embossed knobs shown in FIG. 6d, 6e have rounded or beveled head regions. This too Embossed knob shapes can be used particularly in the second embodiment of the invention as shown in FIGS. 5a, 5b. If in this case the groove N has a narrowing at the edge of the upper side OS of the first component S1 or, compared to the inside of the groove, a narrower width at the outer edge, the insertion area EB of the second component B4 can be driven in by embossed knobs with a rounded or beveled one Head area be relieved. Furthermore, in this case, the groove can have at least one run-in slope E directly at the edge of the upper side OS of the first component S1.

Claims (10)

Method for producing an electromagnetically sealed holder of two metallic components (S1, S2, S3 with B1, B2, B3), in particular for holding a cover plate on a mounting rail of a shielded module rack for electronic modules, whereby a) the first component (S1, S2 or S3) has a groove (N) at the edge of an upper side (OS), which is preferably provided as an extension of the upper side (OS) of the component (S1, S2 or . S3) is covered, b) the second component (B1, B2 or B3) has a knife-like insertion area (EB), and c) after inserting the insertion area (EB) of the second component (B1, B2 or B3) into the groove (N), embossed knobs (P1) in the area of the lamella (L) into the surface (OS) of the first component (S1, S2 or S3). (FIG. 1a to FIG. 4b) Method according to claim 1, wherein in the first component (S3) the lamella (L) has a longitudinal web (ST) on the inside of the groove (N), and the embossed knobs (P1) lie directly above the longitudinal web (ST) in the region of the lamella (L) into the surface (OB) of the first component (S3). (FIG 4a, 4b) Method according to claim 1 or 2, wherein the second component (B2) has countersunk points (SP) on the surface (OB) of the insertion area (EB), in particular troughs, bores or punchings, and the embossing knobs (P1), each lying directly above the individual countersink points (SP) in the area of the lamella (L), are introduced into the surface (OS) of the first component (S1, S2, S3). (FIG 3a, 3b) The method of claim 1 or 2, wherein the second component (B3) on the surface (OB) of the insertion area (EB) has a longitudinal countersink slot (SL2), and the embossing knobs (P1) directly above the countersink slot (SL2) in the area of Slat (L) in the surface (OB) of the first component (S1, S2, S3) are introduced. (FIG 4a, 4b). The method of claim 1, wherein in the first component (S2) the bottom of the groove (N) opposite the inside of the groove below the lamella (L) has a longitudinal slot (SL1), and the embossed knobs (P1) lie directly above the longitudinal slot (SL1) in Area of the lamella (L) in the surface (OS) of the first component (S2) are introduced. (FIG 2a, 2b) Method for producing an electromagnetically sealed holder for two metallic components (S1, B4), in particular for holding a cover plate on a mounting rail of a shielded module carrier for electronic modules, whereby a) the first component (S1) has a groove (N) on an upper side (OS), b) the second component (B4) has a knife-like insertion region (EB), into which embossed knobs (P2) are protruding, and c) the two components (S1, B4) are fixed after inserting the insertion area (EB) of the second component (B4) into the groove (N) of the first component (S1) by jamming the embossing knobs (P2) inside the groove (N ) is effected. (FIG 5a and 5b) The method of claim 6, wherein the groove (N) at the edge from the top (OS) of the first component (S1) has a narrowing or a smaller width than inside. Method according to claim 6 or 7, wherein the groove (N) has at least one run-in slope (E) directly at the edge of the upper side (OS) of the first component (S1). Shielded subrack for holding electronic assemblies, in particular printed circuit boards, with a) a first metallic component (S1, S2 or S3), in particular a mounting rail, which has a groove (N) at the edge of an upper side (OS), which is preferably provided as an extension of the upper side (OS) by a lamella (L) of the component (S1, S2 or S3) is covered, and b) a second metallic component (B1, B2 or B3), in particular a cover plate, which has a knife-like insertion area (EB), and wherein c) the electromagnetically tight fixation of the two components (S1, S2 or S3 with B1, B2 or B3) is effected by embossing knobs (P1), which after inserting the Inserting area (EB) of the second component (B1, B2 or B3) into the groove (N) in the area of the lamella (L) into the surface (OS) of the first component (S1, S2 or S3). (FIGS. 1a to 4b) Shielded subrack for holding electrical assemblies, in particular printed circuit boards, with a) a first metallic component (S1), in particular a mounting rail, which has a groove (N) on an upper side, and b) a second metallic component (B4), in particular a cover plate, which has a knife-like insertion area (EB) with protruding embossed knobs, and c) the electromagnetic tight fixation of the two components (S1, B4) after inserting the insertion area (EB) of the second component (B4) into the groove (N) of the first component (S1) by jamming the embossed knobs (P2) inside the groove (N) is effected. (FIGS. 5a and 5b)

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